The efficacy of glycemic control with continuous glucose monitoring on atheroma progression: rationale and design of the Observation of Coronary Atheroma Progression under Continuous Glucose Monitoring Guidance in Patients with Type 2 Diabetes Mellitus (OPTIMAL)

Current therapeutic guidelines recommend achieving glycated hemoglobin HbA1c <7.0% to prevent macrovascular diseases in type 2 diabetes mellitus (T2DM) patients (1,2). However, several randomized controlled trials demonstrated that stricter control of HbA1c did not necessarily improve their cardiovascular outcomes (3-5). In particular, intensive lowering HbA1c elevates a risk of hypoglycemia which has been shown to associate with higher mortality (5). These observations suggest the limitation of HbA1c-based glycemic control for the prevention of diabetic macrovascular diseases. Given that HbA1c reflects average blood glucose in the past 1–2 months but not serial changes in glucose level including hypoglycemia, the another approach enabling real-time accurate monitoring of glucose level is required